Method of brazing



Dec. 31, 1929. F, P, VINCENT A 1,742,017

METHOD OF BRAZ ING Filed Oct. 4; 1926 2 Sheets-Sheet l N w "D N ,gwen/brn Dec. 31., 1929. F. P. VINCENT v 1,742,017

METHOD OF BRAZING Filed Oct. 4. 1926 2 Sheets-Sheet 2 [NVE/uren i EZMQPM E Yff/Zf A rromvfys Parenteel Dec. 31, 1929 UNITED STATES FRANK P.VINCENT, or ELYEIA, lomo, AssIeNoE, BY MESNE ASSIGNMENTS, T o STEEL ANDTUBES', INC., 0E CLEVELAND, oHIo, A CORPORATION orl oHIo METHOD oFBEAZ'ING Application led October 4, 1926. Seriall No.l 139,331.

This invention relates to a method of brazing. More particularly itrelates to a. method of heating a plurality of elongated articles,

such as tubes, for the'purpose of brazingor4 the like.

An object of thev invention is to provide a process in which articlesmay be uniformly heated on all sides.

Another object is to provide a process in which all articles will beheated alike, ir-

respective of the part of the heated chamber through which they pass. m

vAnother object is to provide a-processv fin which the temperatures ofdifferent parts of .ahea'ted chamber may be readily and independentlycontrolled.

Another object is to provide la process by vwhich articles may bemechanically conveyed l'and'y at thesame time uniformly heated.

Other objects willv hereinafter appear. p AThe invention vwill be betterunderstood from the description of one practical em? bodiment thereofillustrated in the accdmpanying drawings, in which'- Fig. 1 is a planview of the 'furnace and associated parts, the upper part of the furnacebeing shown in section taken on line l-l of Fig. 2;

Fig. 2 is a side elevationof the apparatus shown in Fig.v 1, parts beingshown in section taken on line 2-2 of that figure; and

Figs. 3 and 4 are cross sections of the furnace and the chamber, takenton lines 3-3 and f1-4, respectively, of Fig."'2.

Figure 5 is aslightly enlarged view of a conveyor bar'withtubes thereonshown in section.. i `The furnace consists of a bottom 1, atop 2, anintermediate horizontal wall 3, sides 4 and 5, and `ends 6 and 7. Theintermediate wall divides the interior of the furnace into two chambersor compartments, a lower or heating chamber extending throughout thefurnace and having openingsfQ andl()l in its ends, and an upper orcombustion chamber l tically.

to thecombustion chamber. The air admitted 1s controlled by doors ordampersl atthe outer ends of the passages. A passageA 16 PATENT OFFICE.I

allows the burning gases to pass from the ,l

end of'thecombustion chamber remote'frorn opening 12 to the heatingchambers. In order Yto direct the gases through this passage 1 .andprevent the `setting up of eddy currents, i

the inner surface of the end wal16'i's down-A wardly andoutwardlyinclined'in t-he combustion chamber and below this extends verticallydown to opening 9; l

At the 4end of the` heating chamber opposite passage 16 isa stack -`17'.y Just before the stackat 18l the ceiling Aofthe heating chamberhasashort, .depending step, and the end wall 7 depends slightly further thanthis step, as shown.

It will be noted that'most of the rcombustion chamberll, the passage 16,thel heating chamber 8 and the stack 17 are all of the same width andthat The furnace is constructed material, such as fire brick, and may beprotected and supported by a metal sheathing as shown.' The entirestructure is supported on legs 19.

leso

the sides of all extendl ver-fA of refractory Extending along the bottomof the heating i `chamber and projecting through the openings at bothends are two parallel Apipes 20..

cool enough to not be damaged by the furnace heat.

. Outside the furnace, and in alignment with pipes 20, are two otherpairs ofparallel pipes or rods22 and 23 supported, respectively, ontables 2,4: and 25. These three pairs form a track for a chain vconveyorby which articles are carried through the furnace.

The conveyor consists of two chains driven by sprockets 26 and runningover idler sprockets 27. `The sprockets 26 are rotated in acounterfclockwise direction as shown in Fig; 2, by any suitable sourceof power, through gearing 28 and controlled by a clutch 29.'`

Beyond the chain conveyor, on table 25, is a series of rollers 30 towhich the chain conveyor may deliver articles and this part of the tableis also provided with a transfer cradle composed of shaft 31 and bars 32by the rotation of which articles can be removed laterally from therollers.

The chains of the conveyor carry at frequent intervals cross bars 33arranged to slide along the tops of the track formed by the pipes abovedescribed. These cross bars carry the articles which are to be heatedand may have their upper edge notched as shown or otherwise suitablyshaped to retain the articles. It will be noted that when in the heatingchamber the ends of the bars are well clear of the side walls, therebeing in practice about three inches between the ends of bars and theWalls, and there is a considerable space between the bars and the bottomof the furnace.

This permits the hot gases to readily reach every side of each articleand thus heat it uniformly throughout.

Due to the flaring sides of the combustion chamber near the fuel inletopening, the fuel air and burning gases flow along this chamber withoutsetting up serious eddy currents. The gases also pass through thepassage 16 and along the heating chamber Without material disturbance.It is, therefore, possible, by controlling the air admitted throughports 14 and 15, to control the temperature at different parts of theheating chamber, thus always heating the articles to the desiredtemperature. This is particularly important in brazing, where the metalmust be heated sufficiently to fuse and must not be permitted to burn.

The chain conveyor carries the articles into the furnace at the stackend, where the gases are comparatively cool. and then, as the articlesbecome heated, through progressively hotter parts of the furnace, thusextracting the greatest practicable amount of heat from the gases.

The conveyor may be operated continuously at such a speed that thearticles are heated any desired amount as they pass through the furnace,or may be caused to stop when the articles have been carried into thefurnace and then operated to remove them after they have been heated forany desired period.

Due to the arrangement of the conveyor parts, the heated gases haveready access to all sides of the articles, so that no side is heatedsubstantially more than any other.

While I have described the illustrated embodiment of my invention insome particularity, obviously it may be applied in many other Ways and Ido not, therefore, limit myself to the precise construction shown butclaim as my invention all variations, modifications and embodimentscoming Within the scope of the appended claims.

I claim:

1. The process of brazing tubes which comprises moving a plurality oftubes simultaneously through a chamber, controlling the temperature ofthe chamber, so that the temperature of the tubes is substantiallyuniform on any transverse plane, and controlling the speed at which thetubes are moved so that brazing material is heated sufficiently to fusebut not to burn.

2. The process of brazing tubes which comprises ap lying brazingmaterial to the seams of the tu es, arranging the tubes in groups, eachof Which comprises a plurality of tubes in spaced side-by-side relation,passing the groups successively through a furnace from the cooler end tothe hotter end thereof, While maintaining the tubes at a distance fromall walls of the furnace, controlling the temperature in the furnace byadmitting air at a plurality of points so that the temperature of thetubes is substantially uniform on any transverse plane, and controllingthe speed at which the tubes are moved so that the brazing material isheated just suiiiciently to insure proper fusion.

3. The process of brazing tubes which comprises applying brazingmaterial to the seams of the tubes, arranging the tubes in groups,

each of which comprises a plurality of tubes in spaced side-by-siderelation, passing the groups successively through a chamber Whilemaintaining the tubes at a distance from all walls of the chamber,controlling the temperature in the chamber, and controlling the speed atwhich the tubes are moved so that the brazing material is heated justsufficiently to insure proper fusion.

4. The method of brazing which comprises introducing heated gas into achamber, passing articles to be brazed through the chamber at such aspeed that they are heated by the gas to a brazing temperature, andmaintaining substantially uniform the temperature in the chamber in anyvertical plane at right angles to thc path of travel of the articles.

5. The method of brazing which comprises introducing heated gas into achamber, passing articles to be brazed through the chamber in such amanner that they are heated by the gas to a brazing temperature, andintroducing cooling gas into localized portions of the heated gaswhereby the temperature of the i latter is maintained substantiallyuniform in any vertical plane at right angles to the path of travel ofthe article.

6. The method of brazing which comprises passing heated gas into achamber, passing articles to be brazed through the chamber and heatingthem to a brazing temperature While maintaining them in spaced relationto the walls of the chamber, and maintaining the temperature in thechamber substantially s1gnature.

uniform in any vertical plane at right angles to the path of travel ofthe articles.

7. The method of brazing Which comprises passing heated gas through achamber, controlling thetemperature of the gas so that in any givenplane at right angles to its direction oli' travel the temperature ofthe gas is substantially uniform, and passing arti-y cles to be brazedthrough, thelchamber in a direction opposite to the travel of the gasand lout of contact With the chamber Walls and controlling the travel.of the articles so that they are gradually heatedto brazing temperature.f

8. The method of brazing tubes which comprises passing heated lgasthrough a chamber, passing tubes to be brazed through the chamber in adirection opposite to that of the gas and causing the tubes each yto beheated substantially uniformly in any given transverse plane andgradually heated up to the brazin temperature.

9. The method of brazing tubes which comprises passing heated gasthrough a chamber, passing tubes to be brazed through the chamber inadirect-ion opposite to 'that of the gas and causing the tubes each tobel heated substantially uniformly and all to be heated to substantiallythe same temperature in any given transverse plane and gradually heatedup to the brazing temperature.

In testimony whereof I hereunto affix my FRANK P. VINCENT.

